document.write( "Question 1110573: Brine containing 4 lbs/gal of salt enters a large tank at the rate of 4 gal/min and the solution well-stirred leaves at 2 gal/min. The tank initially contains 30 gal of water. • Set up an equation determining the amount of salt in the tank at any time t in minutes. • What is the amount of salt in the tank after 10 minutes? • When will there be 170 lbs of salt in the tank? \n" ); document.write( "
Algebra.Com's Answer #725634 by addingup(3677)\"\" \"About 
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the salt enters the tank at rate:
\n" ); document.write( "R_in = (4gal/min)(4lbs/gal) = 16lbs/min
\n" ); document.write( "Since the tank loses liquid at a rate of 2gal/min:
\n" ); document.write( "4gal/min - 2gal/min = 2gal/min
\n" ); document.write( "after t minutes the number of gallons of brine in the tank is:
\n" ); document.write( "30 + 2t gallons
\n" ); document.write( "after 10 minutes:
\n" ); document.write( "30 + 2(10) = 50 gallons
\n" ); document.write( "and
\n" ); document.write( "50(4) = 200lbs of salt
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\n" ); document.write( "170/4 = 42.5gallons of brine
\n" ); document.write( "42.5-30 = 12.5 gallons of brine need to be added
\n" ); document.write( "12.5/2 = 6.25 minutes to get 170lbs of salt in the tank
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\n" ); document.write( "I think this is what you were looking for.
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